Systems for the removal of pollutants

ABSTRACT

An inorganically polluted waterway is bridged by a dam containing a wall of carbon. The carbon is continuously regenerated by cycling through a thermal converter. Organically polluted sewage effluent and water from the waterway are continuously mixed and piped to the top of the wall of carbon, passed through the wall of carbon, and clean water is continuously drained from the bottom of the wall of carbon. An alternative installation is positioned adjacent to a restrictedflow body of water in an excavation to maintain the necessary water level differentials.

United States Patent [19] Shaler et al. 1 Jan. 30, 1973 541 SYSTEMS FORTHE REMOVAL OF 3,401,114 9/1968 POLLUTANTS FROM WATER 671,6 9 426,9884/l890 [76] Inventors: Amos .1. Shaler, 705 W. Park Ave., 1,995,3673/1935 Stat C g 6 Daniel 3,436,343 4/1969 Smith ..210 33 x McLean, PO.Box ll7, Elm Street, Lemont, Pa. 16851 Primary Examiner-Samih N. Zaharna[22] Filed: Feb. 22, 1971 Assistant Examiner-Thomas G. WyseAttorney-Robert F. Custard [21] Appl. No.: 117,435

[57] ABSTRACT Cl. An inorganically polluted waterway is a 61/32 damcontaining a wall of carbon. The carbon is con- [51] lnLCl..C02b1/l4,C02c 5/02 [inuougly regenerated by cycling through a thermalField of Search 30, 33, converter. Organically polluted sewage effluentand 210/40, 153, 170, H39, 269, 286 water from the waterway arecontinuously mixed and piped to the top of the wall of carbon, passedthrough References Cited the wall of carbon, and clean water iscontinuously UNTED STATES PATENTS drained from the bottorn of the wallof carbon. An alternative installation 18 positioned ad acent to a3,244,621 4/1966 Bouthilet ..2l0/33 X restricted-flow body of water inan excavation to 802,183 l0/l905 DurbrOW maintain the necessary waterlevel differentials. 3,436,344 4/1969 Canning ct 8|...

58,868 l0/l866 Mietzsch ..2l0/286 4 Claims, 4 Drawing Figures CARBONSUPPLY SEWAGE J EFFLUENT STARTING 8 I MAKE-UP THERMAL CONVERTER POLLUTEDWATER DEWATER CLEAN WATER PATENTEDJM30 I973 3. 7 l 3, 542

SHEET 1 BF 2 INVENTORS Amos-I. Shaler 8 Daniel C. McLean BYa2 ATTORNEYSYSTEMS FOR THE REMOVAL OF POLLUTANTS FROM WATER BACKGROUND OF THEINVENTION 1 Field of the Invention The present invention has as itsprimary object the lowering of the cost of primary purification ofinorganically polluted waters to the point where large bodies of wastewaters or otherwise contaminated waters can be purified to a desirabledegree. Among .such bodies would be millraces, creeks, streams, canals,and small rivers, and certain lacustrine, riverine, and costal inlets,coves, port facilities, and harbors, where the mixing of the waters withthe adjacent greater bodies of water, such as large rivers, lakes, oroceans, is restricted. Such restricted-flow watercourses and inlets arebecoming polluted to the point where their fauna has largelydisappeared, where they constitute a distinct hazard to health andwelfare, and where their corrosive effect is often so great as todestroy the works of man and nature.

An additional object is the provision of an adsorption wall or columnwithin a darn which utilizes the hydrostatic head of a flowing waterwayretained by the dam to drive the water of the waterway through theadsorption wall in order to reduce the pollution in the waterwaydownstream from the dam.

Another object is the utilization of an adsorption wall of carbon withina dam for the dual purpose of removing pollutants from the waterwaywhich the darn bridges and also from the sewage effluent from a primaryor lower sewage treatment plant in the vicinity of this dam.

A further object is the provision of a continuously regeneratingadsorption wall or column of three parts, in which regeneratedadsorption materialand polluted water are added to one top part, spentadsorption material and certain pollutants are removed from a second toppart, and spent adsorption material and additional pollutants areremoved from a bottom part, thereby improving the adsorbability of thewall or column.

2. Description of the Prior Art Biological systems, such as are in usefor sewage treatment, and direct sand, clay or carbon adsorption systemscan only remove suspended solids, microorganisms, and dissolved organicpollutants. Other systems have been developed to remove the inorganicpollutants frommine and mill waters, and these involve, for example, theuse of large quantities of lime for precipitation of the inorganicpollutants. The cost of these systems is such that at present they areonly marginally economical or even so uneconomical that they cannot beused without Governmental partnership, Also they have the disadvantageof producing a secondary disposal problem in the eventual removal of theinsoluble salts precipitated by the reaction between the additive andthe pollutants.

The major problem in the fight against this type of pollution is thatthe economic cost is so large that there is often no apparent way to payfor it except through outright national funding. So far, the majoreffort has been directed at preventing pollution at its source, but thiseffort has not caught up with the problem. There have also been a few,hitherto economically unsuccessful, attempts to recover some at least ofthe costs of decontaminating such waters by recovering the values theycontain, as for instance the iron from the waters polluted by effluentsfrom steel mills. But no large-scale economically valuable system hasyet been successfully operated.

SUMMARY The approach utilized by the applicants has been to find alarge-scale use for the inorganically polluted waters that mightsufficiently offset the cost of decontaminating them. Recentinvestigations have demonstrated that the admixture of ordinarymunicipal sewage effluent with these waters converts to adsorbable forma sufficient number of the inorganic pollutants in sufficient proportionto make possible a substantial decontamination if these converted formscan then be removed in turn from the water-sewage effluent mixture. Thequantity of municipal sewage effluent generated in the vicinity ofpolluted waterways is often large enough to make possible the primarytreatment of large volumes of inorganically polluted waters. Since thesemunicipalities are already prepared to incur the cost of treating theirsewage effluent, if at the same time and with relatively littleadditional expenditure they have the choice of also decontaminating andkeeping relatively clean the waterways that border or traverse theirterritory, a considerably lower expenditure will have to be made than ifan attempt is made to treat the inorganically polluted waters separatelyfrom the sewage effluent. 1

The present invention includes a first installation wherewith thepollution of a millrace, creek, stream, canal, or small river can beremoved after controlled admixture of sewage effluent, and an additionalinstallation wherewith such a method can be applied to the continuousreduction to an acceptable degree of the pollution of inlets on lakes orseashores where the exchange of water with the adjacent greater body ofwater is restricted either by geographical features or by the works ofman, such as port piers, breakwaters and the like. lt is in theserestricted portions of. rivers, estuaries, and oceans that the greatestpollutional problem exists in the first place, since the restriction of.flow prevents the dilution of the waters, andsince it is where theserestrictions exist that man has constructed many communities andindustrial plants. Therefore, since-it is in the vicinity of such bodiesof water that sewage effluent is readily available, both the need andthe solution are present. In flowing waterways also, the greatest needfor depollution is near the municipalities, where the solution, that is,the sewage effluent, is near at hand. Whenever the following terms:waterway, water, water system, or body of water are used throughout thespecification and claims herein, they are to be construed broadly toinclude the appropriate portions of industrial waste lagoons, sanitarylandfill drainage sumps, and their connections to larger water bodies.

Applicants method consists of providing an extensive wall of char oractivated carbon, down the height of which the mixture of sewageeffluent and unclean water is allowed to flow by gravity. Carbon of asize larger than passing through 50-mesh'U. S. Standard Sieve size hasbeen used; however, carbon of other sizes may be used and the individualcarbon particles will fragment or agglomerate during the process toproduce various sizes of carbon particles. The spent carbon is removedfrom the top of the wall at a sufficient rate, and replaced with new orregenerated carbon at a slightly lower rate, so that most of thepollutants are also removed. -A part of the spent carbon, with its loadof organic matter from the sewage effluent and inorganic matter from thewaters combined with it, is

' recarbonized in a thermal converter to provide the new or regeneratedcarbon. But the organics themselves are converted to carbon and gases.This extra carbon is not needed in the next cycle. Therefore, a portionof the spent carbon is not recarbonized, but used as fuel, together withsome combustible'municipal wastes if needed, to provide the heat forthecarboniza tion. This at the same time makes possible the continuousremoval of a corresponding portion of the inorganic matter, which iscarried by the portion of spent carbon used as fuel, in the form of ash.In this form it is ideally suited as starting material for processescapable of recovering whatever values are present in the polluted fiuentin the first place. The sidewalls of the converter r are readily fittedwith boiler tubes capable of recovering, as steam heat suitable forpower generation, the excess heat generated by the converter fire, andindeed, an excess of municipal combustible waste can be disposed of atthe same time to augment such a useful by-product.

In the case of waterways, millraces, creeks, streams, canals, and smallrivers, the necessary flows of water, sewage effluent, and carbon can beobtained by damming the waterway. In the case of inlets, ports, and

other bodies of water without a substantial flow, it will be necessarytodig an excavation to provide the necessary flow of water and sewageeffluent through applicants installation. The capacity of the intakesystem is controlled by valving to a flow such that at mean low waterlevel, the water level above the carbon column remains at a constantlevel. When the water How in the waterway is greater than it is at themean low water level, excess water flows over the dam; this part of thewater is not treated. Since during the high-water periods the pollutionis least on account of greater dilution, this fact does notsubstantially decrease the efficiency of the system; it would bedecreased to a far greater degree if the water loading of the carbonwall were to be allowed to vary in complete dependence upon the waterlevel of the waterway. When the water flow is less than the mean lowwater level, the quantity of water treated is automatically allowed tobecome less; if the balance between sewage effluent and massflow ofpollutant is thereby upset, no harm results, since the converter isperfectly capable of coping with organic pollutants alone, or with anyconcentration ratio of sewage effluent to inorganic pollution greaterthan that occurring at mean low water level.

Along the bottom of the carbon wall a relatively small proportion of thecarbon is extracted for regeneration or recarbonization. The great bulkof the recycled carbon is continuously removed from the top of thecarbon wall along with the bulk of the pollutants, which have beenadsorbed and filtered out principally in that region. The necessity forthe removal of a small portion of the carbon from the bottom of the wallarises from the fact that some pollutant species, primarilysmall-molecule soluble species, are slowly adsorbed,

and would slowly saturate the ca'rbon'wall, if only the' top portion ofcarbon were removed, regenerated, and renewed. Another reason forremoving some of the carbon from the bottom of the carbon wall is thatthe finest particles of carbon would otherwise accumulate and clog thecolumn.

Inside the carbon wall' the water flows downward between the carbonparticles, then upward through screens and discharge pipes having acapacity such that when the flow passing through them is equal to theflow of the waterway at the annual mean low water level,

their back pressure is equal'to the hydrostatic head of v the system.Thus the downward flow through the carbon wall is at all timesapproximately the same, except when the waterway flow is less than atthe mean low water level, when it is less. But this is the time alsowhen the pollution is at its highest concentration and when the flowthrough the carbon wall must be slowest.

From time to time for short periods the flow through the system andcarbon column may be reversed to backwash the screens and temporarilypartially fluidize the carbon wall to prevent long-term decreases in itspermeability.

For bodies of water such as inlets, not having a flow available toprovide a hydrostatic head to drive the flow through the carbon wall, anadditional embodiment is necessary. It simply consists of excavating ahole in the bank of the river, lake, or ocean. This hole is concretelined, and across the middle contains a dam similar to the one describedabove. Polluted water and sewage effluent are continuously allowed toflow by gravity into the hole .on one side ofthe dam, and the cleanwateris continuously pumped out of the hole on the other side,

to maintain a water head. The water is pumped through pipes to adischarge point as far as possible from the installation, preferably tothe point where the main current from the larger adjacent body of waterfeeds into the inlet. In the case of a riverine inlet, the clean waterwould be pumped into the river just downstream from the inlet entrance.Alternately, the clean water can be subjected to secondary and tertiarytreatment and be pumped to the municipal water supply. If a suitablewater body is available at a lower level, the clean water may be draineddirectly into such water body and the pump omitted.

BRIEF DESCRIPTION OF THE DRAWINGS The objectives of the invention andthe manner in which it is carried out will be apparent from thefollowing description and the accompanying drawings, wherein;

FIG. 1 is a plan view showing the orientation of the installationsembodying the invention with respect to the source of polluted waterbeing treated.

FIG. 2 is a vertical sectional viewof an installation embodying one formof the invention. I

FIG. 3 is a sectional view of an additional embodiment of the invention.

FIG. 4 is a diagrammatic flow chart illustrating the flows of water andcarbon through the central portions of the embodiments of the inventionshown in FIGS. 2 and 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a pollutedriver 1, having a flow 2 in the direction of the arrows, is shownbranching into a main channel 5 and a small branch waterway 6. An inlet3 is connected to main channel 5 of river 1 by an area of restrictedwater-mixing 4. Waterway 6 is bridged by a retaining structure or dam 7incorporating an embodiment of applicants invention. Dam 7 is dividedinto two operative units by a vertical wall 77. An excavation 8 ispositioned adjacent to inlet 3. Excavation 8 is bridged by a retainingstructure or dam 107 which divides excavation 8 into two water retainingareas 9 and 10. Retaining structure or dam 107 is similar to retainingstructure or dam'7 and incorporates an additional embodiment ofapplicants invention. Dam 107 is divided into three operative units bywalls 78. It will be understood that, while dam 7 has been shown asdivided into two units and darn 107 has been shown as divided into threeunits, each dam may be a single unit or divided into as many units asconvenient to facilitate repair and renovation. However, at least twounits would be utilized in all cases except where a holding basin isavailable for use during periods of unit shutdown for repairs.

Referring to FIG. 2, waterway 6 which contains a substantial portion ofinorganic pollutants is bridged by retaining structure or darn 7constructed of concrete or masonry. Dam 7 includes an upstream side 11,a downstream side 12, and a generally vertical hollow central portion13. A roof 14 covers central portion 13 of dam 7 and is vented by vent15 to facilitate the escape of gases. Dam 7 is positioned so that thehighest portion 16 is generally horizontal and placed at a levelrepresenting the height of water in waterway 6 at its lowest period ofthe year, the mean low water level 17. The mean water level 18 and themaximum water level 19 of waterway 6 are also shown for purposes ofillustration. A wall of particulate carbon 20 is supported by and withinhollow central portion 13 of dam 7 up to a nominal top level 21. Wall ofcarbon 20 includes a top portion 22 and a bottom portion 23. A bafflestructure 24 generally parallel to the inside surface of dam 7 issupported by rods 25 inset into dam 7 and a support member 69 attachedto roof 14. It will be understood that either rods 25 or support member69 could be used alone, or other support means provided to maintainbaffle 24 in position. Baffle structure 24 is positioned to divide topportion 22 of wall of carbon 20 into a first top part 26 and a secondtop part 27 and restricts the flow of particulate carbon therebetween. Asubstantial vertical gap 28 exists between the nominal top level 21 ofcarbon 20 and underside of roof 14. Within gap 28 and immediately abovefirst top part 26 of wall of carbon 20, a means for adding particulatecarbon 29 is supported by dam 7. Within gap 28 and immediately abovesecond top part 27 of wall of carbon 20, a first means for extractingspent carbon 30 is supported by dam 7. At the lowest central portion ofbottom portion 23 of wall of carbon 20, a second means for extractingspent carbon 31 is supported by dam 7. Means for adding particulatecarbon 29, means for extracting spent carbon 30, and means forextracting spent carbon 31 are conventional commercially availablecomponents. For purposes of illustration, element 31 is shown as ascrew-drive type and element 30 as a traveling design; however, sinceelements 29, 30, and 31 are conventional and commercially available, anyother devices which will perform the desired functions may be utilized.A pipe 32 including an intake end 33 is connected to a manifold 34 whichin turn is connected to the interior of dam 7 by a pipe 35. Additionalpipes 32 and pipes 35 may be provided if the width of waterway 6 makesadditional pipes desirable. Each of pipes 32 is provided with a screenmeans 71. A valve means 36 is positioned within pipe 32 and may beadjusted to be open, closed, or partially closed. Pipe 32, and pipe 35,together with manifold 34 form a conduit connecting the polluted waterin waterway 6 upstream of dam 7 to first top part 26 of wall of carbon20 within hollow central portion 13 of dam 7. A source of sewageeffluent containing substantial amounts of organic pollutants isconnected to a pipe 37 which is connected to manifold 34. A valve means38 is positioned within pipe 37 and may be adjusted to be open, closed,or partially closed. Manifold 34 functions as a mixing chamber for thepolluted water and sewage effluent flowing therethrough, and pipe 35functions as a conduit to discharge the mixture therein into first toppart 26 of wall of carbon 20.

A seriesof pipes 39 including screened water receiving ends 40 leadsfrom bottom portion 23 up through wall of carbon 20 to join a manifold45 which then joins with a drain pipe 41 which leads through downstreamside 12 of dam 7 to discharge clean water downstream. A valve means 42is positioned within pipe 41 downstream of manifold 45 and may beadjusted to be open or closed. Pipes 39, manifold 45, and pipe 41 from aconduit supported by dam 7 for removing clean water from dam 7. Aconduit or pipe 43 from waterway 6 upstream of dam 7 is connected tomanifold 45 to provide a means of backwashing pipes 39 and screenedwater receiving ends 40 whenever necessary to unclog the system and topartially fluidize wall of carbon 20. Pipe 43 is provided with a screenmeans 70. A valve means 44 is positioned within pipe 43 upstream ofmanifold 45, and valve means 44 may be adjusted to be open or closed.

Referring to FIGS. 2 and 4, in normal operation, valve means 36, 38, and42 are open and valve means 44 is closed. Water from waterway 6 andsewage effluent from pipe 37 flow into first top part 26 of wall ofcarbon 20, downward through wall of carbon 20 to screened waterreceiving ends 40, and upward through pipes 39 and 41 back to waterway 6downstream of dam 7. At convenient intervals valve means 36 and 38 areclosed until the water level within dam 7 reaches the level of pipe 41,and then valve means 42 is closed and valve means 44 is opened tobackwash the system and partially fluidize wall of carbon 20. During thebackwash period, the only water flow is from waterway 6, through pipes43 and 39 to screened water receiving ends 40 and up through wall ofcarbon 20 to relieve the compacting which will occur during normaloperation. The water level inside hollow central portion 13 will rise tolevel 21, and then backwashing will be stopped and valve means 36, 38,42, and 44 returned to normal position. Valve means 36, 38, 42, and 44may conveniently be remotely controlled and their positioning shifted byhand or a predetermined mechanical or electrical control means, allconventional and well known in the art. Means for adding particulatecarbon 29 continuously adds rejuvenated carbon to first top part 26 ofwall of carbon 20. Particulate carbon continuously flows downwardadsorbing pollutants which may be adsorbed relatively quickly, underbaffle structure 24, and upward to second top part 27 of wall of carbon20 where the major portion of spent carbon together with the pollutantsadsorbed thereto is removed by means for extracting spent carbon 30. Atthe same, a minor portion of carbon together with other pollutantspecies, primarily small-molecule soluble species which are slowlyadsorbed, is removed by means for extracting spent carbon 31. The reasonfor removing carbon frombottom portion 23 of wall of carbon 20 is thatsmallmolecule soluble species of pollutants would saturate the wall ofcarbon beneath top portion 22, and that the fine particles of carbonwould tend to clog the system.

Pipes 32 and 35 are designed to have a capacity to handle the mean flowof waterway 6 at mean low water level 17. Pipes 39 and 41 together withscreened ends 40 and wall of carbon 20 are designed to have abackpressure equal to the hydrostatic head between nominal level 21 andthe level 46 of the highest portion of pipe 41. Thus, the downward flowthrough wall of carbon 20 is at all times approximately the same, exceptwhen the level of waterway 6 is less than mean low water level 17, whenit is less. But this is the time also when the pollution is at itshighest concentration and when the flow through wall of carbon 20 mustbe slowest to provide time for the adsorption of pollutants. Referringto FIG. 4, the spent carbon removed from wall of carbon 20 is conveyedby conveyors 47 and 48 to a dewatering device 49 and then by a conveyor50 to a thermal converter 54, with a portion being selectively conveyedby a conveyor 51 to join with solid wastes 52 conveyed by a conveyor 53into thermal converter 54. Thermal converter 54 has charring tubes whichcarbonized the spent carbon and the pollutants adsorbed thereon. Therejuvenated carbon is then conveyed by a conveyor 55 to means for addingparticulate carbon 29 for recycling through applicants system. Astarting and make-up carbon supply 73 provides carbon whenever thesystem is started or when needed to supplement the carbon supply to dam7. At times when the pollutants are very heavy, excess carbon may bediverted from conveyor 55 to a conveyor 74 connected to supply 73. Aconveyor 75 is provided to connect supply 73 to conveyor 55 wheneveradditional carbon is needed. At times when pollutants are light, all thecarbon from conveyor 50 may be needed for thermal converter 54, andtherefore a control means 79 is provided to regulate flow withinconveyor 51. Similarly control means 80 and 76 regulate the flow withinconveyors 74 and 75 respectively. Elements 47, 48, 49, 50, 51, 52, 53,54, 55, 73, 74, 75, 76, 79, and 80 are conventional and are included forpurposes of clarity. Thermal converter 54 may be similar to thatdisclosed in U. S. Pat. No. 3,471,369, and the general recycling systemmay be as taught in applicants copending U. S. Pat. applicationentitled: Mechanism and Method for Water Pollution Abatement, Ser. No.844,31 1, filed July 24, 1969, now U. S. Pat. No. 3,622,509. Theinstallation embodying applicants invention will operate satisfactorilyif the new carbon is supplied from another source.

Throughout this application pipes or manifolds have been shown as meansfor delivering water or fluid from one point to another. The termconduit will be used to define one or more connected pipes or manifoldsand any auxiliary attached equipment, such as screen means. In order toprovide the necessary flow crosssection and flow distribution all pipesmay be either of suitable diameter or of manifold design. Further, allconveyors, extractors, means for adding, means for extracting, and theirassociated controls or control means disclosed are conventional and mayinclude all types of prior art devices suitable for the intendedfunction.

The spent carbon contains both the inorganic pollutants from thecontaminated water and the organic pollutants from the sewage effluent.During treatment in converter 54, the latter are converted to carbon andlow-molecular-weight gases. These gases may be vented to the atmosphere,or if they contain harmful or valuable species, they may be scrubbed,selectively adsorbed, or otherwise treated, or they may be added to 7winter particularly, adding the hot gases to the intake would serve toprevent icing in any part of the system. The carbon from the thermalconversion of the organic pollutants joins the carbon that has beenpassed through the water-treatment cycle previously. This wouldcontinuously increase the mass of the circulating carbon load, were itnot for the fact that a portion of the spent carbon is conveyed to thefire box of thermal converter 54 to provide all or a part of the fuelneeded for carbonization; simultaneously, a part of theinorganic-pollutant load is fed to the fire box and ends up as ash, fromwhich values may be recovered. This in turn prevents a continuousbuild-up of inorganic pollutant concentration in the circulating load;in fact, the inorganic load reaches an equilibrium value after severalrecyclings. Other techniques are described in the above-identifiedapplication, Ser. No. 844,31 1, for modifying the activity of thecarbon, and leaching methods may be applied to the spent carbon beforeits recarbonization to modify further the composition of the circulatingload, if desired, by selective dissolution or by ion exchange.

For use in removing inorganic pollutants from lacustrine, riverine, orcoastal inlets, where a hydrostatic head is not available to drive thewater-sewage effluent mixture flows, a modification of the installationof FIG. 2 is necessary. Referring again to FIG. 1, excavation 8 ispositioned adjacent inlet 3. Excavation 8 may be lined with concrete orother water retaining material. Bridging excavation 8 is a retainingstructure or dam 107, similar to dam 7 of FIG. 2.

Referring to FIG. 3 in detail, the portion within dashed lines 56,including dam 107 and all the necessary pipes and valve means is similarin all respects to the structure described with respect to FIG. 2, andthroughout the description of FIG. 3, reference numerals 100 higher thanthose used in FIG. 2 will be used to designate elements similar to thosein FIG. 2. However, since the hydrostatic head of a flowing waterway isnot available, highest portion 116 of dam 107 is positioned at the meanlow water level of inlet 3. A conduit or pipe 57 connects inlet 3 withthe first water retaining area 9 at a level beneath pipe 135. Screenmeans 72 on pipe 57 prevents clogging of pipe 57. A valve means 58 ispositioned within pipe 57 to control the level of water in waterretaining area 9. Valve means 58 will be open at all times unless thewater level in inlet 3 should exceed the highest portion 116 of dam 107,when it would be closed. Water and carbon flow through dam 107 in thesame manner as through darn 7. Clean water discharged through pipe 141collects in a second water retaining area 10 and may be pumped by a pump59 through pipes 60 and 61 to a discharge point remote from dam 107,preferrably returned to' main channel 5 of river 1 downstream from inlet3. If a suitable water body is available at a lower level, pipe 60 andpump 59 may be omitted, as shown in FIG. 1.

Modification to the embodiments shown in FIGS. 1 to 4 include thefollowing: (1) for certain installations the adsorption columnpositioned within a dam and driven by the available water head may bedesirable without the admixture of sewage effluent to the pollutedwater, and with other recharging systems to rejuvenate the adsorptioncolumn; (2) the recharging system disclosed, with the adsorption columndivided into two top portions and a bottom portion, may be desirable forother water depollution systems even when not positioned in a dam.Further, it may be desirable in certain installations to convey thecarbon to be added to the wall of carbon in a flowable form, such as aslurry containing at least percent carbon solids, by weight.

In view of our invention and disclosures, other variations andmodifications will become evident to others skilled in the art, toobtain all or part of the benefits of our invention without copying thestructures and methods shown, and we, therefore, claim all such insofaras they fall within the reasonable spirit and scope of our claims.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent is:

1. In a system for cleaning polluted water, the combination comprising:

a waterway containing polluted water, said waterway having a mean lowwater level and a mean flow at said mean low water level;

a retaining structure bridging said waterway and having an upstreamside, a downstream side, a generally vertical hollow central portiontherebetween, and a roof covering said hollow central portion, thehighest portion of said retaining structure being generally horizontaland positioned a said mean low water level to prevent water below saidlevel from passing over said retaining structure and to permit thatportion of water above said level to pass downstream over said retainingstructure, and said hollow central portion having an interior waterlevel;

a wall of carbon supported within said hollow central portion of saidretaining structure, said wall of carbon being particulate, having a topportion and a bottom portion, and substantially filling said hollowcentral portion up to said interior water level;

a baffle structure supported by said retaining structure, said bafflestructure positioned to divide at least a major portion of said topportion of said wall of carbon into a first top part and a second toppart, and said baffle structure restricting the flow of particulatecarbon within said top portion of said hollow central portion betweensaid first top part and said second top part;

a first conduit connected to a source of sewage and connected todischarge into said first top part of said wall of carbon;

a first valve means positioned within said first conduit intermediatesaid source of sewage and said wall of carbon, said first valve meansnormally open and adapted to control the flow of sewage to said wall ofcarbon;

a second conduit connecting said polluted water in said waterwayupstream from said retaining structure to said first top part of saidwall of carbon, said second conduit having a capacity to handle saidmean flow of said waterway and including an intake end positioned withinsaid polluted water and below said interior water level;

a second valve means positioned within said second conduit intermediatesaid intake end and said wall of carbon, said second valve meansnormally open and adapted to control the flow of polluted water to saidwall of carbon;

a means for adding particulate carbon supported by said retainingstructure, said means for adding connected to a source of particulatecarbon, and positioned so that said particulate carbon is added to saidfirst top part of said wall of carbon;

a first means for extracting carbon supported by said retainingstructure and positioned so that carbon extracted thereby is removedfrom said second top part of said wall of carbon;

a second means for extracting carbon supported by said retainingstructure and positioned so that carbon extracted thereby is removedfrom said bottom portion of said wall of carbon;

a third conduit supported by said retaining structure,

a third valve means positioned within said third conduit upstream fromsaid discharge end of said third conduit, said third valve meansnormally open and adapted to stop the flow of clean water when actuated;

a fourth conduit connecting said polluted water in said waterwayupstream from said retaining structure to said third conduit betweensaid water receiving end thereof and said third valve means;

a fourth valve means positioned within said fourth conduit upstream fromsaid third conduit, said fourth valve means normally closed and adaptedto open a flow of polluted water to said third conduit when actuated;

each of said first, second, third, and fourth valve means adapted to betemporarily reversed to permit said polluted water from said waterway tobackwash a portion of said third conduit and said screened waterreceiving end, and to partially fluidize said wall of carbon; and

the hydrostatic head between said interior water level within saidhollow central portion of said retaining structure and said second waterlevel of said third conduit equals the combined back pressure of saidwall of carbon and said third conduit when the flow passing through thesystem equals said mean flow, whereby the flow through said systemremains substantially constant whenever said polluted water in saidwaterway equals or exceeds said mean low water level.

2. In a system for cleaning polluted water, the combination comprising:

a waterway containing water polluted with substantial amounts ofinorganic pollutants, said waterway having a mean low water level and amean flow at said mean low water level;

a retaining structure bridging said waterway and having an upstreamside, a downstream side, a generally vertical hollow central portiontherebetween, and a roof covering said hollow central portion, thehighest portion of said retaining structure being generally horizontaland positioned at said mean low water level to prevent water below saidlevel from passing over said retaining structure and to permit thatportion of water above said level to pass downstream over said retainingstructure, and said hollow central portion having an interior waterlevel;

a wall of carbon supported by and within said hollow central portion ofsaid retaining structure, said wall of carbon being particulate, havinga top portion and a bottom portion, and substantially filling saidhollow central portion up to said interior water level;

a baffle structure supported by said retaining structure, said bafflestructure positioned to divide at least a major portion of said topportion of said wall of carbon into a first top part and a second topart, and said baffle structure restricting the flow of particulatecarbon within said top portion of said hollow central portion betweensaid first top part and said second top part;

a mixing chamber supported by said retaining structure;

a first conduit connected to a source of secondary sewage effluentcontaining substantial amounts of organic pollutants and connected tosaid mixing chamber;

a first valve means positioned within said first conduit intermediatesaid source of secondary sewage effluent and said mixing chamber, saidfirst valve means normally open and adapted to control the flow ofsecondary sewage effluent to said mixing chamber;

a second conduit connecting said polluted water in said waterwayupstream from said retaining structure to said mixing chamber, saidsecond conduit having a capacity to handle said mean flow of saidwaterway and including an intake end positioned within said pollutedwater and below said interior water level;

a second valve means positioned within said second conduit intermediatesaid intake end of said second conduit and said mixing chamber, saidsecond valve means normally open and adapted to control the flow ofpolluted water to said mixing chamber;

a third conduit connected to said mixing chamber and discharging amixture of said polluted water and said secondary sewage effluent intosaid first top part of said wall of carbon;

a means for adding particulate carbon supported by said retainingstructure, said means for adding connected to a source of particulatecarbon, and positioned so that said particulate carbon is added to saidfirst top part of said wall of carbon;

a first means for extracting carbon supported by said retainingstructure and positioned so that carbon extracted thereby is removedfrom said second top part of said wall of carbon;

a second means for extracting carbon supported by said retainingstructure and positioned so that carbon extracted thereby is removedfrom said bottom portion of said wall of carbon;

a fourth conduit supported by said retaining structure, said fourthconduit including a screened water receiving end positioned adjacentsaid bottom portion of said wall of carbon and a discharge end, saidfourth conduit passing through said downstream side and connecting saidwater receiving end to said discharge end and having a highest elevationat a second water level which is substantially lower than said interiorwater level within said hollow central portion of said retainingstructure;

a third valve means positioned within said fourth conduit upstream fromsaid discharge end of said fourth conduit, said third valve meansnormally open and adapted to stop the flow of clean water when actuated;

a fifth conduit connecting said polluted water in said waterway upstreamfrom said retaining structure to said fourth conduit between said waterreceiving end thereof and said third valve means;

a fourth valve means positioned within said fifth conduit upstream fromsaid fourth conduit, said fourth valve means normally closed and adaptedto open a flow of polluted water to said fourth conduit when actuated;

each of said first, second, third, and fourth valve means adapted to betemporarily reversed to permit said polluted water from said waterway tobackwash a portion of said fourth conduit and said screened waterreceiving end, and to partially fluidize said wall of carbon; and

the hydrostatic head between said interior water level within saidhollow central portion of said retaining structure and said second waterlevel of said fourth conduit equals the combined back pressure of saidwall of carbon and said fourth conduit when the flow passing through thesystem system, the combination comprising:

a first body of water having a first level of pollution; a second bodyof water having a second level of pollution, said second body of waterbeing substanl tially smaller than said first body of water and saidsecond level of pollution being substantially higher than said firstlevel of pollution, said second body of water connected to said firstbody of water by an area of restricted water-mixing;

an excavation positioned adjacent said second body of water;

a retaining structure bridging said excavation and dividing saidexcavation into a first water retaining area and a second waterretaining area, said retaining structure having a hollow centralportion, and said hollow central portion having an interior water level;

a wall of carbon supported within said hollow central portion of saidretaining structure, said wall of carbon being particulate, having a topportion and a bottom portion, and substantially filling said hollowcentral portion up to said interior water level; baffle structuresupported by said retaining structure, said baffle structure positionedto divide at least a major portion of said top portion of said wall ofcarbon into a first top part and a second top part, and said bafflestructure restricting the flow of particulate carbon within said topportion of said hollow central portion between said first top part andsaid second top part;

a first conduit connecting said second body of water to said first waterretaining area at a level to permit water to flow into said first waterretaining area by gravity to maintain a substantial level of water insaid first water retaining area; i

a first valve means positioned within said first conduit, said firstvalve means normally open and adapted to control the flow of water tosaid first water retaining area;

a second conduit connecting said water in said first water retainingarea to said first top part of said wall of carbon, said second conduitincluding an intake end positioned within said water in said first waterretaining area and below said interior water level;

a second valve means positioned within said second conduit intermediatesaid intake end and said wall of carbon, said second valve meansnormally open and adapted to control the flow of polluted water to saidwall of carbon;

a means for adding particulate carbon supported by said retainingstructure, said means for adding connected to a source of particulatecarbon, and positioned so that said particulate carbon is added to saidfirst top part of said wall of carbon;

a first means for extracting carbon supported by said retainingstructure and positioned so that carbon extracted thereby is removedfrom said second top part of said wall of carbon;

a second means for extracting carbon supported by said retainingstructure and positioned so that carbon extracted thereby is removedfrom said bottom portion of said wall of carbon;

a third conduit supported by said retaining structure, said thirdconduit including a screened water receiving end positioned adjacentsaid bottom portion' of said wall of carbon and a discharge end whichdischarges clean water from said retaining structure into said secondwater retaining area, said third conduit connecting said water receivingend to said discharge end and having a highest elevation at a secondwater level which is substantially lower than said interior water levelwithin said hollow central portion of said retaining structure, wherebythe water flow through said wall of carbon is provided by gravity flow;

a third valve means positioned within said third conduit, said thirdvalve means normally open and adapted to stop the flow of said cleanwater when actuated;

a fourth conduit connecting said polluted water in said first waterretaining area to said third conduit between said water receiving endthereof and said third valve means;

a fourth valve means positioned within said fourth conduit, said fourthvalve means normally closed and adapted to open a flow of polluted waterto said third conduit when actuated;

each of said second, third, and fourth valve means adapted to betemporarily reversed to permit said polluted water from said secondwater retaining area to backwash a portion of said third conduit andsaid screened water receiving end, and to partially fluidize said wall'of carbon; and

a means for returning said clean water to said water system at asubstantial distance from said first conduit.

4. In a system for minimizing the pollution in a water system, thecombination comprising:

a first body of water having a first level of pollution;

a second body of water having a second level of pollution, said secondbody of water being substantially smaller than said first body of waterand said second level of pollution being substantially higher than saidfirst level of pollution, said second body of water connected to saidfirst body of water by an area of restricted water-mixing;

an excavation positioned adjacent said second body of water;

a retaining structure bridging said excavation and dividingsaid'excavation into a first water retaining area and a second waterretaining area, said retaining structure having a hollow centralportion, and said hollow central portion having an interior water level;

a wall of carbon supported by and within said hollow central portion ofsaid retaining structure, said wall of carbon being particulate, havinga top portion and a bottom portion, and substantially filling saidhollow central portion up to said interior water level;

a baffle structure supported by said retaining structure, said bafflestructure positioned to divide at least a major portion of said topportion of said wall of carbon into a first top part and a second toppart, and said baffle structure restricting the flow of particulatecarbon within said top portion of said hollow central portion betweensaid first top part and said second top part;

a mixing chamber supported by said retaining structure;

a pipe connecting said second body of water to said first waterretaining area at a level to permit water to flow into said first waterretaining area by gravity to maintain a substantial level of water insaid first water retaining area;

a first conduit connected to a source of secondary sewage effluentcontaining substantial amounts of organic pollutants and connected tosaid mixing chamber;

a first valve means positioned within said first conduit intermediatesaid source of secondary sewage effluent and said mixing chamber, saidfirst valve means normally open and adapted to control the flow ofsecondary sewage effluent to said mixing chamber;

a second conduit connecting said water in said first water retainingarea to said mixing chamber, said second conduit including an intake endpositioned within said water in said first water retaining area andbelow said interior water level;

a second valve means positioned within said second conduit intermediatesaid intake end of said second conduit and said mixing chamber, saidsecond valve means normally open and adapted to control the flow ofpolluted water 'to said mixing chamber;

a third conduit connected to said mixing chamber and discharging amixture of said polluted water and said secondary sewage effluent intosaid first top part of said wall of carbon;

a means for adding particulate carbon supported by said retainingstructure, said means for adding connected to a source of particulatecarbon, and positioned so that said particulate carbon is added to saidfirst top part of said wall of carbon;

a first means for extracting carbon supported by said retainingstructure and positioned so that carbon extracted thereby is removedfrom said second top part of said wall of carbon;

a second means for extracting carbon supported by said retainingstructure and positioned so that carbon extracted thereby is removedfrom said bottom portion of said wall of carbon;

a fourth conduit supported by said retaining structure, said fourthconduit including a screened water receiving end positioned adjacentsaid bottom portion of said wall of carbon and a discharge end whichdischarges clean water from said retaining structure into said secondwater retaining area, said fourth conduit connecting said waterreceiving end to said discharge end and having a highest elevation at asecond water level which is substantially lower than said interior waterlevel within said hollow central portion of said retaining structure,whereby the water flow through said wall of carbon is provided bygravity flow;

a third valve means positioned within said fourth conduit said thirdvalve means normally open and adapted to stop the flow of said cleanwater when actuated;

a fifth conduit connecting said polluted water in said first waterretaining area to said fourth conduit between said water receiving endthereof and said third valve means;

a fourth valve means positioned within said fifth conduit, said fourthvalve means normally closed and adapted to open a flow of polluted waterto said fourth conduit when actuated;

each of said first, second, third, and fourth valve means adapted to betemporarily reversed to permit said polluted water from said secondwater retaining area to backwash a portion of said fourth conduit andsaid screened water receiving end, and to partially fluidize said wallof carbon; and

a means for returning said clean water to said water system at asubstantial distance from said pipe.

1. In a system for cleaning polluted water, the combination comprising:a waterway containing polluted water, said waterway having a mean lowwater level and a mean flow at said mean low water level; a retainingstructure bridging said waterway and having an upstream side, adownstream side, a generally vertical hollow central portiontherebetween, and a roof covering said hollow central portion, thehighest portion of said retaining structure being generally horizontaland positioned a said mean low water level to prevent water below saidlevel from passing over said retaining structure and to permit thatportion of water above said level to pass downstream over said retainingstructure, and said hollow central portion having an interior waterlevel; a wall of carbon supported within said hollow central portion ofsaid retaining structure, said wall of carbon being particulate, havinga top portion and a bottom portion, and substantially filling saidhollow central portion up to said interior water level; a bafflestructure supported by said retaining structure, said baffle structurepositioned to divide at lEast a major portion of said top portion ofsaid wall of carbon into a first top part and a second top part, andsaid baffle structure restricting the flow of particulate carbon withinsaid top portion of said hollow central portion between said first toppart and said second top part; a first conduit connected to a source ofsewage and connected to discharge into said first top part of said wallof carbon; a first valve means positioned within said first conduitintermediate said source of sewage and said wall of carbon, said firstvalve means normally open and adapted to control the flow of sewage tosaid wall of carbon; a second conduit connecting said polluted water insaid waterway upstream from said retaining structure to said first toppart of said wall of carbon, said second conduit having a capacity tohandle said mean flow of said waterway and including an intake endpositioned within said polluted water and below said interior waterlevel; a second valve means positioned within said second conduitintermediate said intake end and said wall of carbon, said second valvemeans normally open and adapted to control the flow of polluted water tosaid wall of carbon; a means for adding particulate carbon supported bysaid retaining structure, said means for adding connected to a source ofparticulate carbon, and positioned so that said particulate carbon isadded to said first top part of said wall of carbon; a first means forextracting carbon supported by said retaining structure and positionedso that carbon extracted thereby is removed from said second top part ofsaid wall of carbon; a second means for extracting carbon supported bysaid retaining structure and positioned so that carbon extracted therebyis removed from said bottom portion of said wall of carbon; a thirdconduit supported by said retaining structure, said third conduitincluding a screened water receiving end positioned adjacent said bottomportion of said wall of carbon and a discharge end which dischargesclean water from said retaining structure, said third conduit connectingsaid water receiving end to said discharge end and having a highestelevation at a second water level which is substantially lower than saidinterior water level within said hollow central portion of saidretaining structure; a third valve means positioned within said thirdconduit upstream from said discharge end of said third conduit, saidthird valve means normally open and adapted to stop the flow of cleanwater when actuated; a fourth conduit connecting said polluted water insaid waterway upstream from said retaining structure to said thirdconduit between said water receiving end thereof and said third valvemeans; a fourth valve means positioned within said fourth conduitupstream from said third conduit, said fourth valve means normallyclosed and adapted to open a flow of polluted water to said thirdconduit when actuated; each of said first, second, third, and fourthvalve means adapted to be temporarily reversed to permit said pollutedwater from said waterway to backwash a portion of said third conduit andsaid screened water receiving end, and to partially fluidize said wallof carbon; and the hydrostatic head between said interior water levelwithin said hollow central portion of said retaining structure and saidsecond water level of said third conduit equals the combined backpressure of said wall of carbon and said third conduit when the flowpassing through the system equals said mean flow, whereby the flowthrough said system remains substantially constant whenever saidpolluted water in said waterway equals or exceeds said mean low waterlevel.
 2. In a system for cleaning polluted water, the combinationcomprising: a waterway containing water polluted with substantialamounts of inorganic pollutants, said waterway having a mean low waterlevel and a mean flow at said mean low water level; a retainingstructure bridging said watErway and having an upstream side, adownstream side, a generally vertical hollow central portiontherebetween, and a roof covering said hollow central portion, thehighest portion of said retaining structure being generally horizontaland positioned at said mean low water level to prevent water below saidlevel from passing over said retaining structure and to permit thatportion of water above said level to pass downstream over said retainingstructure, and said hollow central portion having an interior waterlevel; a wall of carbon supported by and within said hollow centralportion of said retaining structure, said wall of carbon beingparticulate, having a top portion and a bottom portion, andsubstantially filling said hollow central portion up to said interiorwater level; a baffle structure supported by said retaining structure,said baffle structure positioned to divide at least a major portion ofsaid top portion of said wall of carbon into a first top part and asecond to part, and said baffle structure restricting the flow ofparticulate carbon within said top portion of said hollow centralportion between said first top part and said second top part; a mixingchamber supported by said retaining structure; a first conduit connectedto a source of secondary sewage effluent containing substantial amountsof organic pollutants and connected to said mixing chamber; a firstvalve means positioned within said first conduit intermediate saidsource of secondary sewage effluent and said mixing chamber, said firstvalve means normally open and adapted to control the flow of secondarysewage effluent to said mixing chamber; a second conduit connecting saidpolluted water in said waterway upstream from said retaining structureto said mixing chamber, said second conduit having a capacity to handlesaid mean flow of said waterway and including an intake end positionedwithin said polluted water and below said interior water level; a secondvalve means positioned within said second conduit intermediate saidintake end of said second conduit and said mixing chamber, said secondvalve means normally open and adapted to control the flow of pollutedwater to said mixing chamber; a third conduit connected to said mixingchamber and discharging a mixture of said polluted water and saidsecondary sewage effluent into said first top part of said wall ofcarbon; a means for adding particulate carbon supported by saidretaining structure, said means for adding connected to a source ofparticulate carbon, and positioned so that said particulate carbon isadded to said first top part of said wall of carbon; a first means forextracting carbon supported by said retaining structure and positionedso that carbon extracted thereby is removed from said second top part ofsaid wall of carbon; a second means for extracting carbon supported bysaid retaining structure and positioned so that carbon extracted therebyis removed from said bottom portion of said wall of carbon; a fourthconduit supported by said retaining structure, said fourth conduitincluding a screened water receiving end positioned adjacent said bottomportion of said wall of carbon and a discharge end, said fourth conduitpassing through said downstream side and connecting said water receivingend to said discharge end and having a highest elevation at a secondwater level which is substantially lower than said interior water levelwithin said hollow central portion of said retaining structure; a thirdvalve means positioned within said fourth conduit upstream from saiddischarge end of said fourth conduit, said third valve means normallyopen and adapted to stop the flow of clean water when actuated; a fifthconduit connecting said polluted water in said waterway upstream fromsaid retaining structure to said fourth conduit between said waterreceiving end thereof and said third valve means; a fourth valve meanspositioned within said fifth conduit upstream fRom said fourth conduit,said fourth valve means normally closed and adapted to open a flow ofpolluted water to said fourth conduit when actuated; each of said first,second, third, and fourth valve means adapted to be temporarily reversedto permit said polluted water from said waterway to backwash a portionof said fourth conduit and said screened water receiving end, and topartially fluidize said wall of carbon; and the hydrostatic head betweensaid interior water level within said hollow central portion of saidretaining structure and said second water level of said fourth conduitequals the combined back pressure of said wall of carbon and said fourthconduit when the flow passing through the system equals said mean flow,whereby the flow through said system remains substantially constantwhenever said polluted water in said waterway equals or exceeds saidmean low water level.
 3. In a system for minimizing the pollution in awater system, the combination comprising: a first body of water having afirst level of pollution; a second body of water having a second levelof pollution, said second body of water being substantially smaller thansaid first body of water and said second level of pollution beingsubstantially higher than said first level of pollution, said secondbody of water connected to said first body of water by an area ofrestricted water-mixing; an excavation positioned adjacent said secondbody of water; a retaining structure bridging said excavation anddividing said excavation into a first water retaining area and a secondwater retaining area, said retaining structure having a hollow centralportion, and said hollow central portion having an interior water level;a wall of carbon supported within said hollow central portion of saidretaining structure, said wall of carbon being particulate, having a topportion and a bottom portion, and substantially filling said hollowcentral portion up to said interior water level; a baffle structuresupported by said retaining structure, said baffle structure positionedto divide at least a major portion of said top portion of said wall ofcarbon into a first top part and a second top part, and said bafflestructure restricting the flow of particulate carbon within said topportion of said hollow central portion between said first top part andsaid second top part; a first conduit connecting said second body ofwater to said first water retaining area at a level to permit water toflow into said first water retaining area by gravity to maintain asubstantial level of water in said first water retaining area; a firstvalve means positioned within said first conduit, said first valve meansnormally open and adapted to control the flow of water to said firstwater retaining area; a second conduit connecting said water in saidfirst water retaining area to said first top part of said wall ofcarbon, said second conduit including an intake end positioned withinsaid water in said first water retaining area and below said interiorwater level; a second valve means positioned within said second conduitintermediate said intake end and said wall of carbon, said second valvemeans normally open and adapted to control the flow of polluted water tosaid wall of carbon; a means for adding particulate carbon supported bysaid retaining structure, said means for adding connected to a source ofparticulate carbon, and positioned so that said particulate carbon isadded to said first top part of said wall of carbon; a first means forextracting carbon supported by said retaining structure and positionedso that carbon extracted thereby is removed from said second top part ofsaid wall of carbon; a second means for extracting carbon supported bysaid retaining structure and positioned so that carbon extracted therebyis removed from said bottom portion of said wall of carbon; a thirdconduit supported by said retaining structure, said third conduiTincluding a screened water receiving end positioned adjacent said bottomportion of said wall of carbon and a discharge end which dischargesclean water from said retaining structure into said second waterretaining area, said third conduit connecting said water receiving endto said discharge end and having a highest elevation at a second waterlevel which is substantially lower than said interior water level withinsaid hollow central portion of said retaining structure, whereby thewater flow through said wall of carbon is provided by gravity flow; athird valve means positioned within said third conduit, said third valvemeans normally open and adapted to stop the flow of said clean waterwhen actuated; a fourth conduit connecting said polluted water in saidfirst water retaining area to said third conduit between said waterreceiving end thereof and said third valve means; a fourth valve meanspositioned within said fourth conduit, said fourth valve means normallyclosed and adapted to open a flow of polluted water to said thirdconduit when actuated; each of said second, third, and fourth valvemeans adapted to be temporarily reversed to permit said polluted waterfrom said second water retaining area to backwash a portion of saidthird conduit and said screened water receiving end, and to partiallyfluidize said wall of carbon; and a means for returning said clean waterto said water system at a substantial distance from said first conduit.